Presentation: Results of NASA Dawn mission’s study of asteroids Vesta and Ceres

Astronomer Schelte “Bobby” Bus will share highlights from the NASA Dawn mission, paired with a discussion on ground-based observations like those at the NASA Infrared Telescope Facility on Maunakea.

Poster with information that can be found in the body of this post.

SPEAKER: Schelte “Bobby” Bus, Deputy Director, NASA Infrared Telescope Facility, Maunakea.
TITLE: Secrets from Vesta and Ceres: Results of NASA’s Dawn Mission.
DATE: Friday, Jan. 19, 2018.
TIME: 7:00 p.m.
PLACE: ‘Imiloa Astronomy Center, 600 ‘Imiloa Place, off of Komohana and Nowelo Streets at the University Park of Science and Technology, University of Hawai‘i at Hilo (campus map).


NASA’s Dawn spacecraft is on a mission to study Vesta and Ceres, the two largest members of the asteroid belt. These diverse asteroids offer crucial scientific clues into the birth of the solar system some 4.6 billion years ago.

Although the massive asteroids Vesta and Ceres both hold similarities that help with understanding the formation of the Solar System, they have many differences in their geological makeup. Vesta has a rocky body, while Ceres is believed to contain large amounts of water and has an icy surface. Vesta’s south pole contains a massive crater measuring 285 miles across and 8 miles deep—caused by a giant collision that gouged out one percent of its volume. This collision blasted out over a half a million cubic miles of rock into outer space. Scientist believe that this single collision is the cause for about five percent of all meteorites discovered on Earth.

After ten plus years of exploration, the Dawn Mission is nearing its end. The amazing images and measurements that have returned from this mission are leading scientists to a better understanding of the solar system.

Schelte Bus will share highlights from the Dawn Mission, paired with a discussion on the ground-based observations, like those made at NASA Infrared Telescope Facility on Maunakea—which have helped enhance the scientific return from this exciting mission of discovery.

Artist rendering of the Dawn spacecraft.
Artist rendering of the Dawn spacecraft.


Bus received his doctorate in planetary science in 1999 from the Massachusetts Institute of Technology. In 2000, he moved to Hilo to accept a position with the University of Hawai‘i Institute for Astronomy as a staff astronomer at the NASA Infrared Telescope Facility; he became deputy director in 2017. His research focuses on the physical properties of asteroids and how processes such as collisions alter the asteroid belt, helping to feed material like meteoroids and Near-Earth Asteroids (NEAs) into near-Earth space.


General admission tickets are $10, and $8 for ‘Imiloa members (member level discounts apply). Pre-purchase tickets at ‘Imiloa’s front desk or by phone at 808-932-8901.

About ‘Imiloa Astronomy Center

This presentation is part of ‘Imiloa Astronomy Center’s monthly Maunakea Skies program hosted by planetarium technician Emily Peavy. The program includes observational highlights of the current night sky over Hawai‘i, with the audience able to view prominent constellations and stars visible during this time of year. Maunakea Skies planetarium presentations are held on the third Friday of each month.

‘Imiloa is a science education center located on the UH Hilo campus. Its centerpiece is a 12,000 sq. ft. exhibit hall, showcasing astronomy and Hawaiian culture as parallel journeys of human exploration guided by the light of the stars. There is a full-dome planetarium and nine acres of native landscape gardens. The center welcomes approximately 100,000 visitors each year, including 10,000+ schoolchildren on guided field trips and other educational programs.